Skip to Main Content
Due to a lapse in federal funding, this USDA website will not be actively updated. Once funding has been reestablished, online operations will continue.
Data-driven diagnostics of terrestrial carbon dynamics over North AmericaAuthor(s): Jingfeng Xiao; Scott V. Ollinger; Steve Frolking; George C. Hurtt; David Y. Hollinger; Kenneth J. Davis; Yude Pan; Xiaoyang Zhang; Feng Deng; Jiquan Chen; Dennis D. Baldocchi; Bevery E. Law; M. Altaf Arain; Ankur R. Desai; Andrew D. Richardson; Ge Sun; Brian Amiro; Hank Margolis; Lianhong Gu; Russell L. Scott; Peter D. Blanken; Andrew E. Suyker
Source: Agricultural and Forest Meteorology. 197: 142-157.
Publication Series: Scientific Journal (JRNL)
Station: Northern Research Station
View PDF (7.47 MB)
DescriptionThe exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth's climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale eddy covariance flux observations from towers to the continental scale by integrating flux observations, meteorology, stand age, aboveground biomass, and a proxy for canopy nitrogen concentrations from AmeriFlux and Fluxnet-Canada Research Network as well as a variety of satellite data streams from the MODIS sensors. We then use the resulting gridded flux estimates from March 2000 to December 2012 to assess the magnitude, distribution, and interannual variability of carbon fluxes for the U.S. and Canada. The mean annual gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem productivity (NEP) of the U.S. over the period 2001-2012 were 6.84, 5.31, and 1.10 Pg C yr-1, respectively; the meanannual GPP, ER, and NEP of Canada over the same 12-year period were 3.91, 3.26, and 0.60 Pg C yr-1,respectively. The mean nationwide annual NEP of natural ecosystems over the period 2001-2012 was0.53 Pg C yr-1for the U.S. and 0.49 Pg C yr-1 for the conterminous U.S. Our estimate of the carbon sink for the conterminous U.S. was almost identical with the estimate of the First State of the Carbon Cycle Report (SOCCR). The carbon fluxes exhibited relatively large interannual variability over the study period. The main sources of the interannual variability in carbon fluxes included drought and disturbance. The annual GPP and NEP were strongly related to annual evapotranspiration (ET) for both the U.S. and Canada, showing that the carbon and water cycles were closely coupled. Our gridded flux estimates provided an independent, alternative perspective on ecosystem carbon exchange over NorthAmerica.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, email@example.com if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationXiao, Jingfeng; Ollinger, Scott V.; Frolking, Steve; Hurtt, George C.; Hollinger, David Y.; Davis, Kenneth J.; Pan, Yude; Zhang, Xiaoyang; Deng, Feng; Chen, Jiquan; Baldocchi, Dennis D.; Law, Bevery E.; Arain, M. Altaf; Desai, Ankur R.; Richardson, Andrew D.; Sun, Ge; Amiro, Brian; Margolis, Hank; Gu, Lianhong; Scott, Russell L.; Blanken, Peter D.; Suyker, Andrew E. 2014. Data-driven diagnostics of terrestrial carbon dynamics over North America. Agricultural and Forest Meteorology. 197: 142-157.
KeywordsCarbon sink, Carbon source, Disturbance, Eddy covariance, Drought, EVI
- A continuous measure of gross primary production for the conterminous United States derived from MODIS and AmeriFlux data
- Assessing net ecosystem carbon exchange of U.S. terrestrial ecosystems by integrating eddy covariance flux measurements and satellite observations
- Carbon fluxes and interannual drivers in a temperate forest ecosystem assessed through comparison of top-down and bottom-up approaches
XML: View XML